VIDEO: Sneak Peek - ONCE UPON A TIME's 'A Curious Thing'

Below, get a sneak peek at the next episode of ABC's Once Upon a Time titled "A Curious Thing" - what is it that Zelena wants Snow's baby for? The episode airs Sunday, April 27th at 8:00-9:00 p.m., ET on ABC.

Master storytellers Edward Kitsis and Adam Horowitz ("Lost," "Tron: Legacy") invite everyone to join the members of Storybrooke as they try to discover why Zelena wants Snow White's baby. The battle between evil and wicked continues as Henry's life is threatened. Will Glinda be able to save them?